x86: disable intel_iommu support by default
Due to recurring issues with DMAR support on certain platforms.
There's a number of filesystem corruption incidents reported:
https://bugzilla.redhat.com/show_bug.cgi?id=479996
http://bugzilla.kernel.org/show_bug.cgi?id=12578
Provide a Kconfig option to change whether it is enabled by
default.
If disabled, it can still be reenabled by passing intel_iommu=on to the
kernel. Keep the .config option off by default.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 73f7fe8..9c39095 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1802,6 +1802,17 @@
and include PCI device scope covered by these DMA
remapping devices.
+config DMAR_DEFAULT_ON
+ def_bool n
+ prompt "Enable DMA Remapping Devices by default"
+ depends on DMAR
+ help
+ Selecting this option will enable a DMAR device at boot time if
+ one is found. If this option is not selected, DMAR support can
+ be enabled by passing intel_iommu=on to the kernel. It is
+ recommended you say N here while the DMAR code remains
+ experimental.
+
config DMAR_GFX_WA
def_bool y
prompt "Support for Graphics workaround"